Snowpack and Avalanche Discussion
<p>Very dangerous avalanche conditions exist in the Bridger Range north of Bozeman. In the last 36 hours, 27” of snow, equal to 2.8” of SWE, rapidly loaded the snowpack. And it is still snowing. <strong>Persistent slab avalanches </strong>will break deep in the snowpack and propagate across wide areas, and avalanches within the new and wind-drifted snow will be large enough to injure or kill a skier or rider. Yesterday, during the peak storm, a skier on the south side of Bradley’s Meadow was caught by an avalanche; thankfully, they were unharmed (<a href="https://www.mtavalanche.com/node/33144"><strong><span>details</span></s…;).</p>
<p>Natural and human-triggered slides are likely. Traveling in backcountry avalanche terrain is not recommended. Backcountry travelers may trigger avalanches from flat terrain below steeper slopes.</p>
<p><span>The avalanche danger is HIGH on all slopes.</span></p>
<p>A week of snowfall ended yesterday with snow totals measuring in the feet. Significant loading from new and wind-drifted snow results in dangerous avalanche conditions across the forecast area south of Bozeman through Island Park and Cooke City.</p>
<p><strong>Storm Totals from the Last Week: </strong></p>
<ul>
<li>Bridger Range: 34” of snow (3.5” SWE)</li>
<li>Cooke City, Island Park and S. Madison Range: 22-25” of snow (2.5-2.9” SWE)</li>
<li>Lionhead, Northern Madison and Northern Gallatin Range: 19-24” of snow (1.8-2.3” SWE)</li>
</ul>
<p><strong>Persistent slab avalanches </strong>can break across widely across slopes, failing on buried weak layers 1-3 feet deep (deeper on wind-loaded slopes), and avalanches breaking within new and wind-drifted snow, more sensitive to human triggers, will be large enough to bury or injure a rider or skier.</p>
<p><strong>Recent Avalanche Activity:</strong></p>
<ul>
<li>Yesterday, a skier in Cooke City reported several large collapses and a natural avalanche that broke 500 feet wide and 4-6 feet deep high on Henderson Mountain (<a href="https://www.mtavalanche.com/node/33139"><strong><span>photos and details</span></strong></a>)</li>
<li>My partner and I had only skinned twenty minutes in Beehive Basin before triggering an avalanche on a test slope that propagated 150 feet wide, breaking one foot deep (<a href="https://www.mtavalanche.com/node/33133"><strong><span>media and details</span></strong></a>)</li>
<li>Last weekend, we received vague reports of an avalanche that partially buried a rider in the Lionhead area (<a href="https://www.mtavalanche.com/node/32662"><strong><span>details</span></s…;), a snowmobiler triggered slides in Cabin Creek on test slopes (<a href="https://www.mtavalanche.com/node/33083"><strong><span>photos</span></st…;), and Ian and Alex saw a couple of small slides on Lionhead Ridge (<a href="https://www.mtavalanche.com/node/33108"><strong><span>obs and photo</span></strong></a>).</li>
</ul>
<p>Employ cautious route-finding that minimizes exposure to slopes steeper than 30 degrees and avalanche runout zones. Avoid steep wind-loaded terrain in upper mountain bowls and at high elevations.</p>
<p><span>The avalanche danger is CONSIDERABLE. Today, if snowfall exceeds forecast amounts, expect increasing danger.</span></p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Wednesday, January 8, 2025, 7-9:30 p.m., Avy Savvy Night at the Colonial Theater, Idaho Falls. More information HERE.
